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I could obtain the simulation of my multibody with kinematic closed chain (CKC).

However, it seems that from a specific time (around 12s) in my model I believe that I have some numerical instabilities. Indeed, I could compare my simulation results with another mulbody software. I obtain the same simulation until 12s and after in MapleSim, it appears many perturbations as you can see on the figures belows.

So, I think that I tune the numerical solver. This numerical solver must solve DAEs equations since my model contains 4 kinematic closed loops.

If i read correctly the help menu, there are the following methods to solve the DAEs :

- use specific DAE numerical solver (3 differents solvers are used : ck45 method, RKF45 method and Rosenbrock method

- use reformulation equations techniques (Baumgarte, Projection) which can be associated (I believe) with a classic solver like (RK4).

For the moment, I have obtained my results with the rosenbrock solver with error absolute : 1.0*10^(-4) and eror relative :error absolute : 1.0*10^(-4) 

Do you have some ideas or advices so as to find a better method to solve my multibody systems with kinematic closed loops ? This method should  prevent the creation of numerical instabilities.

Thanks a lot for your help


I am using Maple 15 to numerically solve a system of differential algebraic euqations (DAE) with given initial conditions, and I've tried rfk45_dae and rosenbrock_dae solver, but both solver responded in error like this


Error, (in dsolve/numeric) cannot numerically solve complex DAE initial value problems, the system must be converted to a real system


I don't understand what is a real system, and how could i convert it to a real system.


I would like to solve the a sytem of 5 differential equations for a combution process and i dont know how to do.


my enties are as follows


PDEtools[declare](prime = t);
print(`output redirected...`); # input placeholder
derivatives with respect to t of functions of one variable will

   now be displayed with '
MW = 29;
print(`output redirected...`); # input placeholder


I have made a model in classic maple of a mechanical system. But, as this model is a a model of a kinematic closed system, it leads to DAEs equations. Consequently, i need to use specific tool to solve my DAEs.

I know that MapleSim can solve this kind of problem.

So is it possible to use numeric solver used in MapleSim in classic Maple to solve my DAE equations ?

How can i do to call this solver from classic Maple ?

Thank you for help.



I'm trying to solve a pretty complex system of equations (a 3rd order DAE with 61 equations) using the MEBDFI numeric solver but I'm always getting the following error.


error in dsolve/dae/numeric/sm_intersect. numeric exception, division by zero


I have tried to find out what the sm_interesect command is but I haven't had luck neither in Internet nor in Maple help. I have looked for similar posts...

Further tags : implicit form, Matlab codegen for GPOPS purposes

Hi there,

I would like to introduce my self and ask you for an advice. 

I have a four linked robot that i would really like to control by the meaning of the optimal control theory. The arm has 4 actuators (giving torques U) in corrispondence of 4 rotational joints. P parameters describe the system.

I got ht edynamic system with the Lagrangian method and now I have 4 2nd order...

I have another differential equations that I can't find the integral of its solution by applying above 2 methods. Maple runs more than 10 mins without results. These equations are attached in this comment.

I really appreciate all your help.

Hi all,

I try many ways to solve the below DAEs, for example stiff=true, method = rkf45_dae, method=rosenbrock..., but my DAEs can't be solved. In different ways, there are different errors, such as "Warning, cannot evaluate the solution past the initial point, problem may be complex, initially singular or improperly set up", ""

Would you please show me how to solve the below DAEs and plot their solutions?

I really appreciate your help.

If I have a MapleSim file that successfully runs and I want to manipulate the data and equations in Maple, how would I do that? I know how to link a MapleSim file to a Maple document, and how to pull out the system of reduced DAE's, ODE's, parameters, etc. My question is whether or not there's a simple way to have Maple solve those equations and be able to display the same type of data (graphs, export the numerical solution to the system to an Excel file, etc.) that...

What is the difference between them?

daesys0:={diff(I3(t),t) = 1/L*u(t), I1(t) = I3(t) + 1/R * u(t), I3(0)=0, I1(0)=0};


daesys0:={diff(I3(t),t) = 1/L*u(t), I1(t) = I3(t) + 1/R * u(t), I3(0)=0};

If I use the procedure for numerical solution, their solutions are similar.


When I try to solve a DAE system I got this error:

               Error, (in dsolve/numeric/DAE/applysub) numeric exception: division by zero

Any ideas?
Thanks everybody for help!

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